1. Field of the Invention
The present invention relates to transporting components for large towers. More specifically, the present invention relates to a system and method for railroad transportation of large flanges and flange assemblies used in the construction and erecting of large towers, such as towers used to support commercial wind turbines.
2. Description of the Related Art
Large-scale wind turbines are used to generate electrical power. Such wind turbines consist of a tall tower with a generator nacelle rotatably coupled about the top of tower's vertical axis. A rotor hub extends out a horizontal axis of the nacelle. Two or more turbine blades are connected to the rotor hub at right angles to the horizontal axis. During operation, prevailing winds cause the turbine blades to rotate about the rotor hub's horizontal axis. The rotational forces are coupled to a generator within the nacelle, which produces electricity. The nacelle rotates about the vertical axis of the tower to maintain the wind turbine blades in proper orientation to the direction of the prevailing winds.
The various components of a large-scale wind turbine may be manufactured at different geographic locations, which may be anywhere in the world. These components are then transported to the ultimate power generation site, assembled, erected, and placed into operation. Since the manufacturing operations may be spread across the world, transportation of the components to the generation site may utilize all modes of transportation, including ships, barges, trains and trucks. The assignee and inventors of the present invention have filed several patent applications and have been issued patents directed to various systems and methods for transporting these components. This invention address issues related to flanges and flanges assemblies for wind turbine blades, generator nacelles, tall tower sections, including transportation and erection matters.
The ever-increasing scale of wind generation systems has now evolved to the point where certain component parts have grown in size beyond allowable freight cargo dimensions and profiles. In particular, flanges and flange assemblies are presently exceeding fifteen feet in diameter, and are expected to become larger in future systems. Suppliers and manufacturers regularly ship flange assemblies separately from tower sections for various reasons, including economics, cost, and supplier source considerations. Thus it can be appreciated that there is a need in the art for a system and method for shipping large flange assemblies via railroad and other intermodal carries in a compact, reliable, safe, and cost effective manner.